1. Field of the Invention
The present invention relates to a distortion correcting apparatus which is particularly applied to a digital camera and corrects a distortion of a photographed object scene image.
2. Description of the Related Art
According to one example of this type of apparatus, image data representing an object scene is firstly subjected to a distortion correction in a horizontal pixel direction by a horizontal-distortion correcting circuit. The image data outputted from the horizontal-distortion correcting circuit is written in a moving image area of an SDRAM. The moving image area is formed by two memory banks, and the image data is written in the two memory banks so that writing banks differ among pixels adjacent in a vertical pixel direction. The image data thus accommodated in the moving image area is thereafter read out in the vertical pixel direction by each horizontal 64 pixels. The read-out image data is subjected to a distortion correction in the vertical pixel direction by a vertical-distortion correcting circuit provided with 48 line memories.
With respect to a distortion in the object scene image, the largest distortion is found at both ends in a length direction and the smallest distortion is found at a center in the length direction both in horizontal and vertical directions. In spite of this, the number of pixels read out from the moving image area for the vertical distortion correction is fixed to 64 pixels. Thus, there is a limit moving image area for the vertical distortion correction is fixed to 64 pixels. Thus, there is a limit to the performance of the vertical distortion correction.